Automatic regulating valve for fluid-operated motors



L. c. BAYLES AND F. M. SLATER.

' AUTOMATIC REGULATING VALVE FOR FLUID'OPERA TED MOTORS.

APPLICATION FILED FEB.27, 1920.

. 1,414,168. d Ap 25, 1922.

O 0 O O i O O so p a? v 4 13.

' 33 m k {M @I VENTORS 25 20 15 16' 1o a y w 'ATT ix-i UNITED STATES PATENT OFFICE.

LEWIS C. BAYIIES AND FRED M. SLATER, OF EASTON, PENNSYLVANIA, ASSIGNORS TO ING-ERSOLIa-RAND COMPANY, OF JERSEY NEW JERSEY.

CITY, NEW JERSEY, A CORPORATION OF AUTOMATIC REGULATING VALVE EORIIJUID-OPERATED MOTORS.

To all whom it may co'rwem Be it known that we, LEWIS C. BAYLES and FRED M. SLATER, both citizens of the United States, residing at Easton, in the county of Northampton and State of Pennsylvania,

have invented a certain new and useful Improvement in Automatic'Regulat-ing Valves for Fluid-Operated Motors, of which the following is a specification.

. This invention relates to percussive tools and in particular to one having an independent fluid actuated motor for rotating the drill while it is being struck by a piston or hammer. More particularly the invention relates to a valve for controlling the supply of motive fluid to the rotating motor to vary the amount of fluid being supplied and maintain substantially constant speed under different conditions of use and air.

adjusted to maintain the speed of the rotating motor constant under variable conditions of use, and furthermore to provide a manually adjustable device by means of which valve may be, so varied-that any desired speed may be maintained on the motor irrespective of the drag or load on the motor.

Afurth'er object of the invention is to enable this regulating valve to be located in the backhead of the percussive tool where it may be disassembled without interfering with the other parts of the drill.

With these and other objects in view, our invention consists in the features of construction operating as set forth in the accompanying specification. 1

Referring to the figures of the drawing, Figure 1, shows a longitudinal plan of a complete tool provided with the present invention, some of the parts being shown in section.

Figure 2, a longitudinal elevation of the present invention with parts of the tool shown in section.

Figure 8, an enlarged transverse sectional view of the operating motor and automatic valve shown diagrammatically.

Specification of Letters Patent. Patented Apr, 25, 1922, Application filed February 27, 1920. Serial No. 361,758. I

piston or hammer 2, striking a drill steel, 3,

at the forward end of its stroke. The hammer may be reciprocated in any usual way and may be of any suitable form, the motive fluid used being commonly compressed air or steam.

In order to rotate the drill steel, a motor 4, is provided, comprising two spur gears". 5, shown diagrammatically in Figure 3. R0- tation of this motor 4 rotates shaft 6' supported by roller bearings 9 at each end, and gearing 7 and provides rotation for the chuck 8 in which the drill steel 3 is nonrotatably inserted. The fluid for operating the hammer and also the rotating motor 4 enters the tool at the inlet 10 which may be in the backhead 11 of the tool. Within the backhead 11 is a constant pressure chamber 12, from which the fluid is distributed to the cylinder. From the constant pressure chamber 12 a conduit 13 permits fluid to pass into the casing of the rotation motor 4 and a valve 15 controls the opening of this conduit 13 and forms the principal subject matter of the present invention.

The fluid after passing through the motor escapes through aonduit l4 and passes to a chamber 18 srrrounding the shaft 6 and escapes to the atmosphere through small openings 19. which mufiies or silences the screech produced when air passes through motors of this type.

The valve 15 comprises a conical head 16 having flutes 17 cut in its tapered sides so that when the valve is in its retracted .position a small amount of fluid may enter. the motor casing 4 through the flutes 17. At the rear end of the valve 15 is a piston head 20 operating in a pressure tight chamber 21. Pressure chamber 21 isclosed by a cover plate 22 through which extends astem 23 having a knurled head 24. A pin 25 is made fast to the stem 23 and pressing against this pin at one end and against the valve at its other end is an expansion spring 26 so that there is-always a pressure tending to force the valve 15 into its widely opened position.

In order to vary the pressure of spring 26 against the valve, the cover plate 22 is provided on its portion which enters the pressure chamber 21 with a. cam surface indented at intervals as shown at 27. Each of the indentations 27 is at a different dis tance from the end of the. valve chamber and provides a depression in which the pin 25 may rest and be locked firmly in place.

1 rotating the gears 5 comprising the motor.

force the alve the spring .At the same time motive fluid is supplied to conduit 30 from the motor casing into the valve chamber 21, thus creating a pressure in this chamber 21 and assisting the spring to force the valve head '16 to its open position. The air pressure and spring pressure on valve 15 is'resisted by the full line pressure against the head 16, thus tending to force the valve 15 to its closed position. The pressure in the motor casing is materially less than the main line pressure in chamber 12, in view of the speed of rotation of the motor and due to the relative size of conduit 13, so that the air pressure against the valve piston head 20 forcing the valve 15 to its open position is relatively light. I

, In starting operation of the drill, as soon as pressure is admitted to the chamber 12 the valve 15 is forced to'its closed position allowing but little air to enter the motor casing through the flutes 17. This amount of air is suflicient to bring the speed of the motor 4: up to that desired when running freely As soon as the drilling is commenced an additional load is placed on the motor,

the speed of the motor is out down and the pressure in the admission side of the motor is increased, thus increasing the pressure behind valve piston head 20, and the valve is permitted to open more widely. With vari-. ations in the load on the motor and its constant eifect upon the speed, variations in pressure are produced in the admission side of the motor andthe position valve 15 is automatically varied accordingly, to in-i crease or decrease the amount of fluid admitted to the motor needed. To prevent the pressure building up a forward portion 31 of the chamber a leak: port 32 is provided connecting this end of the chamber to atmosphere to exhaust pressure which may develop therein.

it is thermore to be noted that the air pressure achamber e as a force on the conical head it of the 1 vs 15 Leno lief o that the valve 15 will assume a predetermined position dppendent upon the pressure in chamber 12. he taper of the head 16 of valve 15 and the flutes 17 are such that the opening around the valve head 16 will vary inversely with the varying line pressures so as to permit enough air to pass and maintain a substantially constant quantity of flow to the motor, and will also maintain a constant speed of the motor through any variations of the air pressure. "As valve head 16 moves in with increased pressure, the air is throttled as desired. By changing the tension on the spring 26 another speed of the motor is obtained but this will be constant with different air pressure.

We claim:

1. In a fluid operated percussive tool, the combination of a fluid operated rotation motor, a supply passage leading-thereto, a valve adapted to automatically vary the opening through said pamage inversely as the line pressure so as to. maintain a substantially I constant quantity of flow to the motor wit varying line pressure, and adapted to automatically vary the said opemng inversely with the speed of the motor so as to maintain approximatel constant motor speed "under varying 10a s, said valve being actuated in one d rectlon-by llne pressure and 1n the other direction by spring pressure and the pressure of the motor. a I

2. In a fluid operated percussive tool, the combination of a fluid operated rotation motor, a supply passage leading thereto, a valve adapted to automatically vary the opening through said passage inversely as'the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and adapted to automatically vary the said opening inversely with the speed of the motor so as to m-ain-. tain approximately constant motor speed under varying loads, said valve having a head constantly subjected to main line pressure tending to move the valve in a direction to reduce the opening through said passage, and-a larger head operating in a valve chamher and subjected to both spring pressure and to the varying pressure in the admission side of the motor for moving the valve in the opposite direction.

3. In a fluid operated percussive tool. the combination of a fluid operated =0 ation motor, a supply passage leading th adapted to automatically var through said passage inversely as the pressure so as to .maintain a substan" constantquantity of flow to the motor v varying line pressure, and adapted at in one direction by line pressure the adapted to automatically vary the opening through said passage inversely as the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and adapted to automatically vary the said open1ng inversely with the speed of the motor so as to maintain approximately constant motor speed under varying loads, said valve having a head constantly subjected to main line pressure tending to move the valve in a direction to reduce the opening through said passage, a larger head operating in a valve chamber and subjected to both spring pressure and to the varying pressure in the admisslon side of the motor for moving the valve in the opposite direction, and means for adjusting said spring pressure. a

5. In a fluid operated percussive tool, the combination of a fluid operated rotation motor, a supply passage leading thereto, a valve adapted to automatically vary the openingthrough said passage inversely as the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and adaptedto automatically vary the said opening inversely with the speed of the motor so as to maintain approximately constant motor speed under varying loads, said valve having a conical fluted head constantly subjected to main line pressure tending! to move the valve in a direction to reduce the opening through said passage, the flutes permitting a restricted passage for motive fluid to the motor when the conical head is in retracted position, and means including both spring pressure and the varying pressure in tho. admission side of the motor for moving the valve in the opposite direction.

6. In a fluid operated percussive tool, the

combination of a fluid operated rotation motor, a supply passage leading thereto, a valve adapted to automatically vary the opening through said passage inversely as the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and adapted to automatically vary the said opening inversely with the speed of the motor so as to maintain approximately constant motor speed under varying loads, said valve having a conical fluted head constantly subjected to main line pressure tending to move the valve in a direction to reduce the opening through said passage, the flutes permitting a restricted passage for motive fluid to the motor when the conical head is in retracted position, means including both spring pressure and the varying pressure in the admission side of the motor for moving the valve in the opposite direction, and means for adjusting said spring pressure.

7. In a fluid operated percussive tool, the combination of a fluid operated rotation motor, a supply pasage leading thereto, a valve adapted to automatically vary the opening through said passage inversely as the line pressure so as to maintain a substantially constant quantity offlow to the motor with varying line pressure, and adapted to automatically vary the said opening inversely with the speed of the motor so as to maintain approxlmately constant motor speed under varying loads, said valve having a conical fluted head constantly subjected to main line pressure tending to move the valve in a direction to reduce the opening through said passage, the flutes permitting unrestricted passage for motive fluid to the motor when the conical head is in retracted position, and the taper of the conical head acting to cause variations in throttling of the fluid'with movements of the valve, said valve also having a larger head. operating in a valve chamber and subjected to both spring pressure and to the varying pressure in the admission side of the motor opposing the main line pressure.

8. In a fluid operated percussive tool, the combination of a fluid operated rotation motor, a supply passage leading thereto, a valve adapted to automatically vary the opening through said passage inversely as the line pressure so as to maintain a substantially constant quantity of flow to the motor with varying line pressure, and

adapted to automatically vary the said open: ing inversely with the speed of the motor so as to maintain approximately constant motor speed under varying loads. said valve having a conical fluted head constantly subjected to main line pressure tending to move the valve in a direction to reduce the opening through said passage, the flutes permitting a restricted passage for motive fluid to the motor when the conical head is in retracted position, and the taper of the conical head acting to cause variations in throttling of the fluid with movements of the valve, said valve also having a larger head operting in a valve chamber and. subjected to both spring pressure and to the varying pressure in the admission side of the motor opposing the main line pressure, and means for adjusting said spring pressure.

9. In a fluid operated percussive tool, the combination of a fluid operated rotation motor. and a valve for automatically regulating the flow of motive fluid to said rotation motor, said valve having a head constantly subjected to main line pressure tending to in a valve chamber and subjected to both spring pressure and to the varying pressure in the admissionside of the motor opposing the main line pressure, a leak port being provided in ,the valve chamber to prevent pressure building up therein on'one side of said piston head, to oppose the combined spring and fluid pressure, whereby the set eur hands.

r flexes speed of the motor is maintained substantially constant regardless of variations of both-load and main line pressure.

- In testimony whereof, we have hereunto LEWIS C. BAYLES. FRED M. SLATER. 

